This invention relates generally to electronic arrays, and more particularly, to methods and apparatus suitable for assembling accurately aligned electronic sensor arrays.
Electronic sensors and transmitters are often configured in arrays to transmit or receive data in a two dimensional format or to effect a desired resolution for a given area. For example, at least one known sensor includes a photodiode including an array of photosensitive pixels coupled to a scintillating medium, which can also be configured as an array of scintillator cells. When subjected to x-ray energy, the scintillator generates optical photons which in turn excite the underlying photosensitive pixels within the photodiode thereby producing an electrical signal corresponding to an incident photon flux.
Assembly of a computed tomographic (CT) detector array requires high precision alignment of more than 50 sensor elements. In at least one known system, a detector array comprises a plurality of sensor elements. Each sensor element in the known CT detector array comprises an x-ray scintillator deposited on an array of photodiode visible light sensors. Thus, sensor elements are referred to herein as “sensor arrays.” Each sensor array must be aligned to an x-ray collimator structure as well as to its neighboring sensor arrays in the detector array. Such precise alignment requires overcoming a number of complications. Each sensor array has flat, parallel inner and outer faces and the sensor arrays are set against a curved collimator rail. Because the rail is curved, edges of the inner face of each sensor array (i.e., the face closest to the collimators and the x-ray source) are closer to adjacent sensor arrays than edges of the outer face. Detector arrays are tested after alignment and the sensor arrays comprising a detector array are bolted in place when testing is complete. Test results are used for iterations of swapping of sensor arrays to optimize overall performance. This swapping requires dismounting and subsequent realignment of sensor arrays in new positions along the collimator rail. Thus, alignment procedures tend to be expensive and time-consuming. Moreover, the procedures do not scale well to detector arrays comprising two-dimensional arrays of sensor arrays, for example, three adjacent rows of over 50 sensor elements.